INTERACTIVE EFFECT OF SALINITY AND POTASSIUM ON GROWTH, BIOCHEMICAL PARAMETERS, PROTEIN AND OIL QUALITY OF SOYBEAN GENOTYPES

Potassium (K+) nutrition ensures growth and quality of crops both under normal and saline soils. In view of that a study was conducted to assess the impact of various doses of K+ on growth, bio-chemicals, protein and oil contents of four soybean (Glycine max L.) genotypes under saline condition. Soybean genotypes were grown in pots having treatment combination of salinity (control, 6 and 12 dS m(-1)) and K+ doses (control, 50 and 75 kg ha(-1)). The results showed that sufficient K+ nutrition enhanced plant growth, biomass production, protein and oil percentage of soybean genotypes both in normal and saline condition. Water relation in plant as well as chlorophyll contents and leaf area improved with the application of potassium under salinity stress. Across K+ application rates, all soybean genotypes significantly varied from each other. K+ accumulation was positively correlated with growth and other parameters of soybean genotypes, but these relationships were stronger in case of genotypes No. 62 and No 13 as compared to Ajmeri and William-82 genotypes. Soybean genotypes No. 62 and No. 13 classified as potassium efficient genotypes while Ajmeri and William-82 categorized as potassium inefficient genotypes on the basis of growth and K uptake.